Showing papers on "Urban climate published in 1993"
TL;DR: In the US, counter-urbanization was associated with several redistribution reversals that were linked to both metropolitan size and region of the country as mentioned in this paper, and Frey and Speare concluded that the 1970s was a "transition decade" for population redistribution in the US.
Abstract: Urbanisation patterns in the United States have taken some unlikely turns over the past quarter of a century. After following fairly predictable trends in the 1950s and 1960s towards increased urban growth and westward movement, the nation experienced a 1970s 'counter-urbanisation' similar to that which occurred in many other developed countries (Champion, 1989; 1992). In the US, counter-urbanisation was associated with several redistribution reversals that were linked to both metropolitan size and region of the country. In assessing these reversals at great length, Frey and Speare (1988) concluded that the 1970s was a "transition decade" for population redistribution in the US. However, the term 'transition' did not refer as much to the specific geographical patterns of redistribution that had emerged, as it did to the changing social and economic contexts for urban and regional growth. The changing national industrial structure, the rise of the global economy and improvements in communications and production technologies, have changed the geography of opportunities across space and the ability of populations to respond to these changes. At the same time, the diffusion of 'urban' amenities to all parts of the country-including areas previously considered to be remote or rural-has expanded the location options for both employers and residents. More so than in the past, the population and economic growth of regions, metropolitan areas and small places are dependent on how successfully these areas can adapt to rapidly changing circumstances. Despite the realisation that the contexts for urban and regional redistribution had been altered, there was little consensus among scholars as to the form of urbanisation that would emerge in the 1980s and 1990s. With findings from the 1990 US census now in hand, the broad dimensions of the new urbanisation in the US can now be detected. Three of these dimensions appear to be significant and are likely to continue to characterise US urban growth for the next decade. First, there is a return to urbanisation-but not the urbanisation of the 1950s and 1960s. New patterns of urban growth and decline are faster paced. They reflect continuing shifts in industrial structure and favour areas with diversified economies, particularly those engaged in advanced services and knowledge-based industries. Over the 1980s, recreation and retirement centres also did well. However, many small and nonmetropolitan areas, particularly in the interior part of the country, fared poorly under the adverse period influences of the 1980s, and as a result of their dependence on less than competitive industries. Growth prospects for these areas are unstable, at best, unless they can diversify their economic bases. Hence,
137 citations
TL;DR: In this article, the authors used the Advanced Very High Resolution Radiometer (AVHRR) at channel 4 (10.5-11.5 μm) on the NOAA-9 and NOAA-10 satellites to examine the applicability of the AVHRR thermal data to the study of urban heat islands.
76 citations
Journal Article•
TL;DR: A summary of all human biometeorologically effective complexes, as well as other factors which are relevant to urban planning and which depend on atmospheric conditions in urban structures in a direct or indirect manner are presented.
Abstract: This article deals with the part of urban climatology which is of particular relevance to human beings. Presented first is a summary of all human biometeorologically effective complexes, as well as other factors which are relevant to urban planning and which depend on atmospheric conditions in urban structures in a direct or indirect manner. Later, methods for human biometeorologically significant assessment of thermal and air pollution components of the urban climate are discussed in detail, because these components can be strongly influenced by urban planning. The application of these methods is illustrated by some results of appropriate investigations in urban areas
74 citations
TL;DR: In this article, an observational and modeling study of the microclimate of a suburban area, as related to the physical and biological nature of the site, is presented in comparison with a nearby open agricultural location or "control site".
36 citations
TL;DR: In this article, the main conclusions from analyses of different alternatives for land use and developmental patterns in three Norwegian urban areas were analyzed, and it was shown that there is relatively little popular support for urban policies in favour of more conservation of land and less use of automobiles.
Abstract: By concentrating the urban developmental pattern, confining new buildings to areas where technical encroachments on nature have previously taken place, and by utilizing each building site efficiently, considerable advantages can be achieved where the overall goal is to preserve nature and maintain environments. These are the main conclusions from analyses of different alternatives for land use and developmental patterns in three Norwegian urban areas. However, there is relatively little popular support for urban policies in favour of more conservation of land and less use of automobiles. Politicians and bureaucrats are less negative than voters to such a change in urban policies.
29 citations
TL;DR: In this article, the effects of artificial heat sources and ground shading by buildings on air temperature variations in the urban canopy layer were analyzed in an idealized urban cluster composed of repeated street canyons oriented east-west with an aspect ratio of 0.5.
Abstract: Simulations are presented for the effects of artificial heat sources and ground shading by buildings on air temperature variations in the urban canopy layer. An idealized urban cluster composed of repeated street canyons oriented east-west with an aspect ratio of 0.5 is used to evaluate these effects. The simulations by the cluster thermal time constant model show that a daily mean artificial heat flux of 11 Wm−2 causes an almost invariant temperature rise of 0.7 K around-the-clock. Conversely, increasing the shade area in the streets by means of vertical screens fitted at the building roof-level can produce a pronounced temperature lowering at midday.
29 citations
01 Jan 1993
TL;DR: The history of Chicago's landscape as it has evolved from a mixture of prairie, wetlands, and oak-hickory forests into a major metropolis is described in this article.
Abstract: The report traces the history of Chicago's landscape as it has evolved from a mixture of prairie, wetlands, and oak-hickory forests into a major metropolis. An analysis of 1987 aerial photographs indicates that Chicago-area tree cover has increased from a presettlement level of about 13 percent to nearly 20 percent today. Street trees predominate in Chicago's residential areas, where buildings and paving restrict tree cover in many off-street locations. Larger percentages of tree cover were found for off-street trees in suburban Cook and DuPage Counties. Chicago's urban climate is associated with increases in rainfall and flooding, summertime temperatures and air conditioning use, and unhealthy levels of ozone. The potential of urban vegetation to improve environmental quality is reviewed and the Chicago urban Forest Climate Project research plan is described.
18 citations
TL;DR: In this article, the detailed energy balance data developed as part of the Tanzania Urban Energy Project was used to analyze urban energy use in three Tanzanian cities and found that the energy-use patterns of the three cities are largely consistent with the expectations derived from the theory of economic specialization across the urban hierarchy.
17 citations
TL;DR: In this article, an overview of the problems in urban land use and the impacts of economic reforms and planning policies on rapid urban land expansion and structural transformation is outlined, followed by statistical analyses to reveal determinants of urban land size.
Abstract: Recent economic reforms and shifts in land use planning in China have greatly changed the size and structure of urban land use In this paper, an overview of the problems in urban land use and the impacts of economic reforms and planning policies on rapid urban land expansion and structural transformation is outlined This is followed by statistical analyses to reveal determinants of urban land size The study shows that urban land use in China has been improved, and urban land use size is related to urban reforms, urban land use adjustment, as well as to population growth and economic development
15 citations
Dissertation•
01 Jan 1993
TL;DR: In this paper, the interactions between residential land development and urban policy in Greece, with special reference to the case of Greater Thessaloniki providing an understanding of the contradictions in urban policy during the period 1974-89.
Abstract: This thesis surveys the interactions between residential land development and urban policy in Greece, with special reference to the case of Greater Thessaloniki providing an understanding of the contradictions in urban policy during the period 1974-89. The starting point is a speculation that institutional attempts to reform urban policy and planning throughout the period 1974-89 remained largely inactive. We hold that this inefficiency is an outcome of a compound political, economic and institutional process linked to the characteristics of residential land development. Main emphasis is paid on: the role of land policy in determining the modern forms of landownership, the impacts of a widespread small landownership upon the pattern of residential development, and, finally, the way politics and ideology are enmeshed in policies related to the residential development process. From a theoretical standpoint it is argued that the analysis of land development phenomena and the attempts to manage them should the traditional distinctions between the analysis of land development and policy analysis. This interdisciplinary approach should also embrace an understanding of structural influences, whether economic political or institutional, with individual strategies, whether of a specific agent or the final investor in or consumer of land. The research is largely based on a historical analysis of state land policy implemented throughout the years 1917 up to contemporary periods. Special emphasis is given to the role of land allocation programmes, which were implemented for the refugee rehabilitation in inter-war years and created a great legacy in land policy. A national account of this policy is provided and the formulation of the first town planning machinery is discussed. The problems and contradictions in urban policy formulation during 1974-89 are examined against the actual institutional practice. A detailed account of state land policy and its repercussions on the structure of urban landed property and the residential development process in Greater Thessaloniki is provided examining more closely the nature and the problems of urban policy and planning in Greater Thessaloniki.
Journal Article•
TL;DR: In this paper, the surface conditions treated in this study are morphology of urban surface (mainly building height, roughness, sky view and energy consumption), heat island intensity and population, population and sky view factor, respectively.
Abstract: The recent studies of the earth's surface conditions relating to heat islands in Japan are presented from geographical viewpoints as an activity of the Association of Japanese Geographers. Urban climate is defined as the result of urbanization, which is expressed as concentration of population, modification of earth's surface constituent materials, and expansion of living space onto and under the ground. These bring about changes in morphological and physical features of the urban surface, and its energetic conditions, which consequently and unintentionally modify radiation, heat and water balance in urban areas. Some estimations of urban surface conditions are at first explained. Surface conditions treated in this study are morphology of urban surface (mainly building height), roughness, sky view and energy consumption. Next, the relationships were considered between air temperature and surface morphology, heat island intensity and population, population and sky view factor, respectively. Finally the regional differences in heat islands were discussed, and the necessity of urban climate studies to ameliorate human and global conditions.
01 Jan 1993
TL;DR: In this article, a precipitation pattern was combined with Koppen climate classes to form a five-class Global Climate Scheme for Urban Climate Studies (GCS/UCS) that explains observed diurnal variations of urban heat island (UHI) magnitude in different climatic zones.
Abstract: A precipitation pattern scheme was combined with Koppen climate classes to form a five-class Global Climate Scheme for Urban Climate Studies (GCS/UCS) that explains observed diurnal variations of urban heat island (UHI) magnitude in different climatic zones. The validity of this scheme was demonstrated using urban/rural micrometeorological field measurements obtained during summer and winter in four cities. Nighttime UHI magnitude was found to increase monotomicly with increasing population, independent of season, climate type, or causal mechanism. Daytime UHI magnitude versus population values, however, showed an interesting dichotomy between results for dry and wet rural soils. Wet-soil rural sites produced daytime UHIs larger than their corresponding nighttime values due to high rural latent heat flux values and high rural thermal inertia values (relative to those of urban materials). With dry rural soils, daytime UHIs were smaller than corresponding nighttime values due to the low thermal inertia of the rural soil (relative to that of urban materials). This produces a rapid daytime rural warming/nighttime cooling and hence weak daytime/strong nighttime UHIs.
Journal Article•
TL;DR: The author discusses the development and functions of urban areas and towns in China and considers elements of urban area; internal and external functions; relationships among urban areas; and the evolution, growth, and changes of towns.
Abstract: The author discusses the development and functions of urban areas and towns in China. Aspects considered include elements of urban areas; internal and external functions; relationships among urban areas; and the evolution growth and changes of towns and their functions. (ANNOTATION)
01 Jan 1993
TL;DR: Wang et al. as discussed by the authors analyzed the change in total urban population and found that urbanization progress can be controlled mainly by social-economic development and government policy through influencing the migratory growth of urban population.
Abstract: Since 1949, great changes have taken place in the amount and distribution of China’s urban population. From the analysis on the change in total urban population, it can be learnt that urbanization progress can be controlled mainly by social-economic development and government policy through influencing the migratory growth of urban population and the number of organic cities. In the period 1949-1990, the states of megalopolises had gone up; medium-sized cities had decreased. It is estimated that the total urban population of China will still increase at a rapid speed in the coming 10 years; there will not be great changes in grade system of urban scale; and urban population may shows a tendency to move to coastal area.
TL;DR: In this paper, the authors defined the characteristics of Chinese urbanization as: the industrialization launched by the government; the simultaneous development of urbamzation of cities and urbanization of rural areas; the quite low capability of urbanization to absorb nonagricultural labor force; the incoordinate development of cities, etc.
Abstract: Since cities and towns are places where those nonagricultural industries are centralized, urbanization is greatly interrelated with industrialization and de-agriculturalization. By means of this kind of interrelationship, Chinese urbanization level may be estimated with the formulas:P1=I1/I0/u0, Pr=N1/N0/u0. The urbanization after the founding of the People’s Republic of China can be divided into the following 5 stages: the stage at the out set of industrialization (1949–1957); the high-speed urbanization stage (1958–1960); the first counter-urbanization stage (1961–1965); the second counter-urbanization stage (1966–1976); and the high-speed urbanization stage (1978-now). The characteristics of Chinese urbanization are: the industrialization launched by the government; the simultaneous development of urbamzation of cities and urbanization of rural areas; the quite low capability of urbanization to absorb nonagricultural labor force; the incoordinate development of cities, etc. Before establishing a specific way of urbanization, it is necessary to determine some strategical principles of the future urbanization, for example, the principle of giving consideration to both economic results and social results, the principle of the combination of strongpoints, the principle of employing both governmental and nongovernmental launching mechanisms, the principle of combining intensive urbanization and extensive urbanization, the principle of paying equal attenion to both urban urbanization and rural urbanization, the principle of combining concentration and dispersion, etc. With the dual urbanization in China and the arduous shifting task of rural surplus labor, the dual urbanization strategy of urbanizing both urban and rural areas should be carried on.
TL;DR: The influence of human activities on environment and climate change is the most conspicuous problem of the Loess Plateau, and it may be divided into two aspects: firstly, the excessive utilization of land by the human race causes the destruction of vegetation, and consequently large expanse of land is under desertification and the characteristics of the ground surface and the water and heat exchange on the ground surfaces have changed.
Abstract: The influence of human activities on environment and climate change is the most conspicuous problem of the Loess Plateau, and it may be divided into two aspects: firstly, the excessive utilization of land by the human race causes the destruction of vegetation, and consequently large expanse of land is under desertification and the characteristics of the ground surface and the water and heat exchange on the ground surface have changed; secondly, the use of coal by industries produces a huge amount of carbon dioxide and trace elements, which enter into the atmosphere to cause air pollution.